Chris Brown just scored an enormous victory in his child custody war with his baby mama ... he got joint custody of Royalty, and he gets to take her home today ... TMZ has learned.

Brown and Nia Guzman squared off in a Houston court Friday morning. She not only wanted to deny Chris any custodial rights, she also only wanted to give him supervised visitation.

The judge disagreed and we've learned Chris and Nia will share 50/50 physical custody, with Royalty going back and fourth every 4 days. Both Chris and Nia now live in L.A.

And Chris, who was in court represented by Mark Geragos, scored another victory. The judge ordered him to pay Nia $2,500 a month in child support, which is exactly what he's been paying her. She wanted $15k.

The judge also ordered Nia not to talk crap on Chris and not reveal anything about the case on social media. 2:00 PM PT -- Nia's legal team has a positive outlook on the hearing. We're told they see it as merely a temporary victory for Chris, since there will be a mediation in weeks to come -- and child support payments will be addressed.

Also, Chris agreed that his mother would always be present when he has custody of Royalty.